The inspection of large and complex objects (such as, solid steam turbine rotors) can be very difficult. Such inspection is important for identifying features, such as, asperities, voids, defects, fatigued material, cracks, and/or material variations. In large objects, non-destructive techniques are limited based upon the size of the objects, based upon the complexity of the objects, and/or based upon the materials of the objects. A failure to identify such features can result in extended repair cycles, limiting availability of operation, and/or system failure.
Some commercial inspection systems are available to provide the inspection of large objects. Known ultrasonic techniques use single probe approaches, limiting the volume of material that can be inspected in a single pass. For example, one known technique, pulse echo, is limited to covering a small volume of a cylindrical solid rotor material in a single pass.
To achieve such inspection in a non-destructive manner, ultrasonic systems can be integrated into the object at a substantial expense, can require complex and/or repeated analysis, can require advanced motion control and/or complex probe positioning control, and combinations thereof, resulting in high costs.
An ultrasonic detection method and ultrasonic analysis method that do not suffer from one or more of the above drawbacks would be desirable in the art.